In order to enable high contrast video images to be reproduced regardless of image content, known gray-scale correction circuits divide the screen into a plurality of areas, calculate the mean value of the luminance signal in each area, create a luminance histogram of the mean luminance values in the areas, and control the input-output characteristic of a gray-scale correction means according to the luminance histogram (e.g., Patent Document 1). Patent Document 1: Japanese Patent Application Publication No. 2004-023522 (paragraph 0011, FIGS. 1 and 2)